ANKARA, Turkey – The imprisoned leader of a Kurdish rebel group fighting Turkey has called for a mass mobilization of all Kurds against the Islamic State militant group which is fighting Kurdish forces in Syria.

In a message relayed through his lawyer late Monday, Abdullah Ocalan said: "I call on all Kurdish people to start an all-out resistance against this high-intensity war."

"Not only the people of Rojava (Syrian Kurdistan) but also all people in the north (Turkey) and other parts of Kurdistan should act accordingly," lawyer Mazlum Dinc quoted Ocalan as saying.

The call came hours before the United States and five Arab countries on Tuesday launched airstrikes against the Islamic militants in Syria.

Ocalan, who is serving a life sentence on a prison island near Istanbul, leads the Kurdistan Workers' Party, or PKK, which has long fought Turkey for autonomy. PKK is affiliated with a Kurdish party in Syria whose armed wing is fighting the Islamic State group in northern Syria.

The Islamic State group's offensive against the northern Syrian city of Kobani, a few miles from the Turkish border, has sent 130,000 refugees to seek safety in Turkey in the last few days.

Hundreds of Kurds from Turkey have clashed near the frontier with Turkish police, who fired tear gas and water cannons. The Kurds say Turkey is hampering their efforts to cross into Syria and help their brethren.

Kurds dominate a region that straddles Iran, Iraq, Syria and Turkey.

Ocalan also accused Turkey of stalling peace negotiations aimed at ending a three-decade-long conflict, while Murat Karayilan, a PKK commander based in northern Iraq, accused Turkey of collaborating with the Islamic militants and declared the peace process to be dead, the pro-Kurdish news website Firat News said.

However, Karayilan said Ocalan would have the "final say" on the future of peace efforts.